The Greek verb thnēskō (θνῄσκω) is a verb for physical death — the act of dying or the state of being dead. It is most commonly found in the perfect tense (tethneken) to describe one who is dead. It is related to thanatos (death) and distinguishes physical death from spiritual death (apothnēskō or nekros in different contexts).
Thnēskō underscores the reality of physical death throughout the New Testament. The resurrection narratives employ this word's cognates to affirm that those Jesus raised were genuinely dead — Jairus's daughter, Lazarus, the widow's son. John 11:44 — 'the dead man came out' — uses this root. The theological significance is that Jesus has power over authentic, physical death, not mere unconsciousness. His own resurrection conquered this same death. Romans 5:12 traces death's universal reign to Adam, while 1 Corinthians 15 celebrates Christ's victory: 'Death has been swallowed up in victory.'